This invention relates in general to ball joints, such as are commonly used in vehicular steering and suspension applications to transmit force between a steering mechanism and a steered wheel of a vehicle. In particular, this invention is aimed at avoiding accidental separation of the ball joint assembly due to wear of both the ball and the socket. The invention also allows for renewal of the ball joint by allowing for replacement of the polymer bearing. The design includes a retainer/safety nut for preventing accidental separation of the components of the ball joint as a result of such wear.
Ball joints are well known structures that are used in a variety of mechanical linkages. For example, ball joints are commonly used in vehicular steering and suspension assemblies to allow front wheels to turn sideways and also to transmit force between a steering mechanism and a steered wheel of a vehicle. A typical ball joint includes a ball stud that is received within a lubricated socket. The ball stud includes a spherically-shaped head portion having an elongated shaft portion extending therefrom. The spherically-shaped head portion of the ball stud is received within and cooperates with a corresponding spherically-shaped recess formed in the socket. This arrangement positively connects the ball stud to the socket so as to permit some forces to be transmitted therethrough. This arrangement also allows the ball stud to pivot in any direction relative to the socket.
It has been found that after a period of use, the cooperating portions of the ball stud and the socket of the ball joint will experience wear. Such wear can create undesirable looseness between the ball stud and the socket of the ball joint, resulting in the generation of noise and misalignment between the ball stud and the socket. In extreme cases, such wear can contribute to or cause the accidental separation of the ball stud from the socket, resulting in a total failure of the ball joint. Accidental separation of the ball stud from the socket is common in areas with bumpy roads. Unfortunately, because the spherically-shaped head portion of the ball stud is received within the corresponding spherically-shaped recess formed in the socket, it is often difficult to determine how much wear has occurred within the ball joint without removing the ball joint from its application and disassembling the ball stud and the socket for inspection. Such removal and disassembly is time consuming and expensive. In extreme cases, wear of the ball stud from the socket can lead to motor vehicle accidents that are caused by the accidental separation of the ball joints or tie rod ends. Thus, it would be desirable to provide a device that prevents accidental separation of the ball joint as a result of such wear. It would also be desirable to provide a method for renewing the ball joint so as to prolong its service life.